Anchor



. s. T. COPE ANCHOR 3 Sheeis-Sheet 1 Filed Dec. 28, 1954 Inve n t or awn/45y 7271/25 60 5, v 9

Attorney s. 'r. I COPE 2,856,881

, ANCHOR s Sheets-Sheet 2 N b-u Oct. 21, 1958 Filed Dec. 28. 1954 v I" sz'v/vu-v PPM/92% Attorney 5. T. COPE ANCHOR Oct. 21, 195

Filed Dec. 28, 1854 s She e cs-Sheet 3 m. 3 50K 3 2" m 8 Attorney AN CHGR Stanley Temple Cope, Teddington, England, assignor to National Research Development Corporation, London, England, a corporation of Great Britain Application December 28, 1954, Serial No. 478,038

Claims priority, application Great Britain December 30, 1953 11 Claims. (Cl. 114-208) This invention relates to anchors of the hinged twin fluke type. and has for its main object to provide an improved anchor of this type which is of relatively lightweight construction particularly suited to manufacture by fabrication methods from sheet steel or light alloy material with a consequent reduction in production costs, and which, at the same time is capable of withstanding loads normally requiring a much heavier and largerdesign of anchor.

Another object of the invention is to provide an improved anchor of the aforementioned type which is of compact design such as to be particularly suited for use on flying boats and high speed marine craft where restricted weight and stowage considerations are of the highest importance.

Anchors as hitherto constructed can be divided generally into two groups, viz. the st-ockless anchor and the stocked anchor. The stockless anchor includes a shank, crown, tripping palm and twin flukes, the said flukes pivoting integrally with the crown and palm atone end of the shank. The stocked anchor, on the other hand may be either of the old Kedge type having a shank from one end of which project two oppositely extending curved arms carrying flukes or palms, and at the other end a long bar or stock fitted at right-angles to the plane of the fluke arms, or the more recent type wherein the :main component parts are the shank, small crown or tripping palm, hinged twin flukes and a long stock passing through the crown directionally in the same plane as the flukes flat surface.

In accordance with the invention an anchor adapted to fulfill the objects above-mentioned comprises a shank, a pair of flukes pivotally connected to and disposed one on each side of said shank, and a stabilizing unit of box-like construction forming an integral structure with the after end of said flukes and composed of a series of stabilizing plates extending outwardly on either side of the flukes at substantially rightangles to the plane thereof and disposed :at intervals across the width of the base of the flukes whilst extending in a direction substantially parallel to the longi- 'tudinal axis of the anchor and to each other so as to provide between the said plates substantially unobstructed longitudinal throughway passages which are also open at the after end of the flukes, the said plates having associated with their outer edges on either side of the flukes, tripping and shank retaining means arranged transversely to said edges.

Conveniently, in carrying out the invention, the stabilizing plates on each side of the flukes, are positioned in alignment with one another in pairs, the two outermost pairs of plates being spaced apart a distance which is less than and within the overall combined width of the bases of the flukes, whilst the two innermost pairs of plates form a central throughway passage within which is wholly housed the means for pivotally connecting the shank to the flukes.

Furthermore, in cases of most exceptional conditions of sea bed, the invention provides for the optional use of a 2,856,881 Patented Qct. 271, 1958 lCC 2 stock whichmay be temporarily secured to the anchor, preferably at the after end of the flukes and at the rear of the stabilising plates.

In order that the invention may be more fully understood and carried into effect, two embodiments thereof will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a plan view of one embodiment of the improved anchor constructed according to the invention, as

it would appear when lying on a flat surface, e Figure 2 is a side elevation of the anchor shown in Figure 1, Figure 3 is an end elevation of the same anchor as viewed from the right-hand side of Figure 1, the anchor being turned through Figure 4 is a section taken on the line 44 of Figure-1,

Figure 5 is a view of the anchor in perspective,

Figure 6 is a plan view of a second embodiment of the improved anchor constructed according to the invention, as it would appear when lying on a flat surface, and Figure 7 is a section taken onthe line 77 of Figure 6.

Referring now to Figures 1 to 5 of the drawings, the anchor comprises three main parts viz., a shank 1, a twin fluke unit 2 and a stabilizing unit 3. At its forward end the shank l is provided with a hole 4 for the shackle pin connection of the shank to the anchor chain (not shown), in the usual manner, whilst at its after end the said shank has another hole 5 which is adapted to receive a hinge pin 6 forming part of the twin-fluke unit 2.

The twin-fluke unit 2 is formed from a single flat plate 7 of substantially triangular shape (see Figure 1) with the base of said triangle at the after end of the anchor and its two opposite sides converging in the forward direction to constitute the respective outer edges of a pair of flukes 3 the inner edges of which are formed by the opposite sides of a slot 9 disposed centrally of the width of the plate and extending longitudinally from the forward end thereof to a point beyond the hinge pin 6 and at some distance from the after edge of said plate. At its inner or closed end the slot 9 is of a width slightly greater than the width of the shank 1 so that the after end of the latter when in the assembled position may be freely accommodated therein to permit relative pivotal movement between the flukes 8 and the said shank about their common hinge pin 6, theopposite edgesof the said slot lying parallel to one another in the vicinity of said hinge pin after which they diverge towards the forward or open end of the slot to form in conjunction with the outer inclined edges of theflukes 8 the pointed bill portions thereof.

As already stated, the hinge pin 6 which is of circular cross-section is secured to the twin fluke unit 2, and in order to do this, the said pin is formed at either end with a diametrical transverse slot 10, the two slots being in alignment with one another and each extending-inwardly towards the other along the length of the pin a distance such as to leave a central solid portion of the pin therebetween of a length substantially the same as the width of the slot 9 and constituting a bearing surface for the after end of the shank 1 when the latter is in position within the said slot 9. The width'of'the slots 10 is such as to permit of their engaging over the surfaces of the flat plate 7 on either side of the slot 9,'and thus allowing the hinge pin 6, after it has been inserted through the hole 5 at the after end of the shank, to be slid (together with the shank) into position along the slot 9 towards the end thereof where said pin is secured in position by means of bolts 11 engaging within holes formed transversely through each end of the pin and through corresponding holes in those portions of the flat plate7 engaged within the transverse slots 10. The ends of the 3 pin 6' are suitably recessed at 12 to provide flat bearing surfaces for the heads of the bolts 11.

The stabilizing unit 3 which is in the form of an open boxflike structure disposed at the after end of the twin fluke unit 2, comprises outer and inner stabilizing plates or fins 13' and 14 respectively, the said plates being arranged in pairs, one on each side of the twin fluke plate 7, at right angles to the plane of the surface thereof and in alignment with one another. The four plates 13 comprising the two outer pairs of stabilizing plates are identical. in shape, each being of general triangular form symmetrically disposed about a central axis YY at rightangles to the opposite surfaces of the fluke plate 7 (Figure 2), with a base 15 and oppositely inclined sides 16. The inclined sides 16 at their inner ends do not join with the base 15 but finish some distance therefrom so as to provide for a pair of sides 17 at right angles to the base 15 and joining the latter to the sides 16, whilst at their outer ends the oppositely inclined sides 16 instead of meeting at a point are cut short some distance from their apex to form an outer edge or side 18 parallel to the base 15. Each pair of plates 13 is fixed in position by welding their bases 15 to the opposite sides of the fluke. plate 7 so that the said plates extend outwardly at rightangles to the said sides in alignment with one another and parallel to the longitudinal axis of the anchor.

The inner stabilizing plates 14, whilst they are also four in number and arranged in two pairs in a similar manner to the outer stabilizing plates 13, are only just over half the length of said outer plates, that is to say, each plate 14 corresponds in general shape and dimensions to that half of the outer plate 13 extending forwardly of the central axis YY (Figure 2). Accordingly, each plate 14 has only one inclined side 16a (Figure 4) which faces forwardly of the anchor, and is inclined at the same angle as the forward side 16 of the corresponding outer plate 13, and one side 17a joining the lower end of the inclined side 16a to the base 15a of said inner plate, the length of the plate being completed by a rear side 19 extending at right angles from the base 15a to the after end of the outer edge or side 18a which latter is the same length and height from the base 15a as the corresponding outer edges 18 from the bases 15 of the plates 13.

The two plates 14 constituting each inner pair are welded at their bases 15a to either side of the fluke plate 7 so as to extend outwardly therefrom and at right angles thereto in alignment with one another in the same Way as the-outerplates 13, and are arranged parallel with the longitudinal axis of the anchor and therefore parallel with one another and with the pair of outer plates 13. The two pairs of inner plates 14 are equally spaced on either side of the shank receiving slot 9 in the fluke plate 7, at a distance apart which is substantially equal to the distance of each of the said pairs of plates from the outer plates 13, and is slightly greater than the length of the hinge pin 6', so as to allow the latter to be fixed in position between the said pairs of inner plates, the rear sides 19 of which extend beyond the said pin to a point forward of the end of the shank receiving slot 9.

All four pairs of stabilizing plates 13 and 14 are thus positioned in transverse alignment across the after end of the fluke plate 7 in a line at right angles to the longitudinal axis of the anchor with their forwardedges 16 and16'a inclined outwardly andrearwardly from the base of each of the said plates, to. provide a series of rearwardly sloping edges with respect to the direction of travelof theanchor over and through the sea bed, and all positioned in a common inclined plane. Also the respective outer edges 18 and 18a of the said plates are at the same height from both sides of the saidfluke plate sothat there isformedbetween the outer and inner stabilizing plates 13 and 14 throughway passages 20 on each. side, of the fluke plate 7 extending fore and aft of the anchor, and a similar central passage 21. betweenthe 4 inner pairs of plates 14 also on either side of the plate 7 and within which is positioned the shank hinge pin 6. At their rear ends the passages 20 and 21 open into transverse passages 22 also formed on either side of the fluke plate 7 and extending across the width of the stabilizing structure between the outer pairs of plates 13.

At their outer edges 18 and 18a on either side of the fluke plate 7, both sets of stabilizing plates 13 and 14 have welded thereto a tripping bar 23 disposed across the said edges at right angles to the longitudinal axis of the anchor and extending over the whole width of the stabilizing structure from one pair of outer plates 13 tothe other pair at the opposite side of the anchor. At the forward transverse edge of each of the said bars 23, along the central portion thereof, there is provided a shank retaining plate 24 which extends alongside and parallel to the said bar from one inner stabilizing plate 14 to the other, the inclined front sides 16a of said plates being provided at their outer ends with recesses 25 within which are welded the opposite ends of said shank retaining plate 24 which latter is also welded along its rear transverse side to the adjacent front transverse side of the tripping bar 23.

The combination of the tripping bars 23 and the shank retaining plates 24 serves not only to give strength and rigidity to the stabilizing plates 13 and 14 as well as maintaining their correct spacing, but also to provide the necessary frictional resistance when the anchor is dragged along the sea bed in line with the axis of the shank 1, thereby'ensuring rapid pivoting of the bills of the flukes 8 in a downward direction to engage the sea bed. In addition, the pair of shank retaining plates 24 serve to determine the range of angular movement of the shank to either side of the fluke plate 7 about its hinge pin 6, the inner transverse edges of'said plates serving as abutments to prevent further movement of the said shank beyond the maximum desired, which range of movement on either side is preferably of the order of 31.

The fiukes 8 may be provided with a pair of longitudinal strengthening ribs or flanges 26 formed one on either side thereof at rightangles thereto and in. alignment with one another, the two pairs of ribs being transversely spaced apart a distance equal to that between the two inner pairs of stabilizing plates 14. Each of the ribs 25 has substantially the same thickness as the plates 14 and is welded along its innerlongitudinal edge to-one or other of the fiukes 8, the outer longitudinal edge of each rib being inclined outwardly from the forward end of the fluke to the after end thereof where it is welded to one or other of the front sides 17a of the inner stabilizing plates 14.

There isthus formed between the ribs 26 on either side of the fluke plate 7, a passageway 27 which extends the whole length of the fiukes 8 and which at its rear end passes between the lower transverse edge of the shank retaining plate 24 and the fluke plate 7 to join up with the central passageway 21 between theinner pairs of stabilizing plates 14. Thus, clogging or fouling of the hinge pin 6 and its associated parts by material from the sea bed,'with possible consequent variation in the critical angle of 31 between the fully pivoted fluke plate '7 and the shank 1 is prevented, since by reason of the passageways 27 and 21, anysuch material forced into said passageways as the anchor is dragged over or through the sea bed, is able to pass therethrough over the hinge pin 6 which is so designed as to offer as relatively little obstruction as possible, and thereby prevent any build-up of the material which is continuously discharged into the open-ended transverse passage 22 at the rear of the stabilizing unit 3. In the same way the passageways 20 between the outer and inner stabilizing plates Band 14 permit of substantially unobstructed freedom of movementof the material of the seabed over the remainder of the surfaces of the flukes 8 extending along the outer sides of the ribs 26, whereby saidmaterial can.pass

from the forward end of the flukes 8 through the passages 20 and under the tripping bars 23 into the transverse passage 22 whence it is discharged.

It will therefore be understood from the above that thestabilizing unit 3 replaces the orthodox crown and tripping palm as well as the stock of previously designed anchors, the functions of which parts are carried out according to the invention by (a) The stabilizing plates 13 and 14 which in themselves serve a triple purpose namely,

(1) To ensure stability of the anchor during burial by preventing rotation of the flukes 8 about the axis of the shank 1.

(2) To provide the necessary points of attachment for the tripping bars 23 and shank retaining plates 24.

(3) To form in association with the tripping bars 23 and the shank retaining plates 24 a box section of great strength to prevent bending of the fluke plates under high loading conditions resulting from deep burial.

(b) The tripping bars 23 and shank retaining plates 24 which in themselves also serve a triple purpose namely,

1) To give rigidity and strength, as well as maintaining correct spacing of the stabilizing plates 13 and 14,

(2) To provide the means of restricting the angular movement of the shank 1 to about 31 with the plane of the flukes,

(3) To provide the necessary frictional resistance when the anchor is dragged along the sea bed in line with the axis of the shank to ensure rapid pivoting of fluke points in a downwards direction and engagement of sea bed.

By way of further hastening the last mentioned effect the fluke plate 7 may be formed with an angle recess 28 ineach of its pair of inclined opposite external sides, one side 28a of said recess being substantially parallel to the longitudinal axis of the anchor to form the outer edge of the fluke 8 whilst the other Side 28b extends outwardly and rearwardly from the rear end of the base of said fluke to join up, at its outer end with the corresponding inclined external side of the fluke plate 7 at a point adjacent the front edge of its associated outer stabilizing plate 13. In this way the fluke plate 7 is provided at its opposite external sides with a pair of inclined shoulder portions both facing in the direction of travel of the anchor over and through the sea bed. Also the forward or fluke portion of the plate 7 is of less overall width than the rear portion thereof carrying the stabilizing unit 3 so that as the anchor is dragged through the sea bed any disturbance and loosening of material is more or less confined to the overall width of the pair of flukes, and material beyond the said flukes on either side thereof remains undisturbed and in its solid form so as to offer a high lateral resistance to the surfaces of the individual outer plates 13 thereby additionally ensuring against rotation of the anchor as a whole about the longitudinal axis. v

As has been previously indicated, the present invention is especially suitable for the construction of a relatively lightweight anchor and, as an example where such'an anchor may have a weight of only 40 lbs., then with reference to the accompanying Figures 1 and 2 the construction illustrated may follow the order of the dimensions indicated as follows:

A (Fig. 1)-2%6" B (Fig. 1 4%" c (Fig. 2 -3%" Referring now to Figures 6 and 7, there is illustrated therein a second embodiment of the anchor according to the invention, which is designed mainly with a view to providing for greater flexibility of use of the anchor so that it will continue to operate successfully even under the most exceptional conditions of sea bed. According to these figures, in which like references are used to indicate parts similar to those of the first embodiment, ananchor having a construction including a shank,

a pair of flukes pivotally connected thereto by means of a shank hinge pin, and a box like stabilizing unit generally as described with reference to the first embodiment shown in Figures 1 to 5, is modified bythe addition of a stock 29 preferably formed of a straight bar of circular section and temporarily secured to the after end of the anchor.

The attachment of the stock 29 to the anchor is preferably effected by inserting the former through holes 30 provided at the rear end of each outer stabilizing plate 13 adjacent the junction of the pair of trailing sides 16 of the said plate. Thus the stock 29, when inserted into position through the holes 30, lies in the same horizontal plane as the flukes 8 and at rightangles to the longitudinal axis of the anchor. In order to permit the stock 29 to be slid into position through and be supported by the two stabilizing plates 13, provision is made for the said plates to extend, at the junction of ,their outer inclined edges, some distance rearwardly beyond the after edge of the fluke plate 7 to provide a space 31 for the reception of said stock.

To allow for the projection of the stock beyond the stabilizing plates 13 on either side of the anchor, those portions of the fluke plate 7 which in the previously described embodiment extended beyond the said plates, are omitted, the side edges of the fluke plate 7 lying flush with the stabilizing plates 13 and parallel to the longitudinal axis of the anchor. With this arrangement, the stabilizing plates 13 instead of each being constituted by a pair of separate plates extending outwardly from either side of the fluke plate 7 and welded at their bases to the said fluke plate, can each be made in the form of a single plate extending across the fluke plate at either side thereof and welded along its center portion to the corresponding edge of the fluke plate, thereby simplifying the fabrication of the stabilizing unit and at the same time increasing its strength.

The stock may be retained in position by any suitable means, as for example, by the provision at a suitable distance from one end thereof, of a cotter pin 32 which can be inserted through a hole in the stock so as to rest against the outer face of one stabilizing plate 13 and position the stock transversely of the flukes 8, a second cotter pin 33 being provided at the other end of the stock at such a distance from the first mentioned pin as to lie adjacent the outer face of the other stabilizing plate 13.

Also in this embodiment, the two inclined front edges 16 of each outer stabilizing plate 13 may be reinforced by a rectangular plate 34 extending outwardly from the side of said plate on either side of the anchor so as to lie in the same inclined plane as the said edges and overhang the plate 13. The plates 34 may be secured in position by being welded along their inner longitudinal edges to the inclined edges 16 so as to form a continuation thereof, and by similar welding of their top transverse rear edges to the front edges of the tripping bars 23 which latter also overhang the stabilizing plates 13.

There is thus provided according to the second embodiment, a stock which is not permanently attached to the anchor, but is available, if required, in the form of a temporary fitting which, by simply removing the cotter pins, can be quickly dismantled from the anchor proper, for the purposes of stowage or replacement.

Furthermore, by reason of the pivotal connection of the shank to the flukes being rendered easily detachable by means of the hinge pin and bolts assembly common to both embodiments, it is only a matter of simply withdrawing the two cotter pins in the stock and the two bolts in the shank pin hinge, in order for the anchor to be readily dismantled into its principal parts consisting of (a) the stock, (b) the flukes assembly including the stabilizing unit integral therewith, and (c) the shank, thereby facilitating the repair and reinstatement or exchange, 1

of any one of such parts, as also the It will be understood that for most types of sea bed the first embodiment of anchor according to the invention would operate efliciently, and it is only in exceptional cases, such as when anchoring in one position for long periods, anchoring in doubtful holding ground under bad weather conditions, or anchoring on a very hard sea bed where the vertical stabilizing plates would not penetrate, that provision is made, as in the second embodiment of anchor according, to the invention, for the optional use of a stock to meet such contingencies.

By making provision for the stock as an accessory, i. e. not always an essential part of the main anchor, stocks of any desired length may be used to suit not only varying types of sea bed but also the different uses to which the anchor may be put. For example, if the anchor is to be employed on a permanent mooring in soft, cozy liquid mud, it might require a stock at least equal to the length of the shank. On the other hand, on a hard, chalky sea bed, a stock at least 25% in excess of shank length might be necessary to ensure positive penetration. In normal types of sea bed, such as sand and mud, clay, mud and small stones, which probably cover 95% of anchoring conditions, no stock would probably be necessary.

I claim:

1. An anchor comprising a shank, a fluke unit formed from a single flat plate of generally triangular shape having its base disposed at the after end of the anchor, said fluke unit having a slot formed therein extending centrally along the greater part of its length from the forward end thereof, said slot terminating in a closed end some distancefrom the base so as to form a pair of fiukes and a connecting portion which joins the flukes together at their after ends, said shank extending into said slot between said flukes and being pivotally connected to the fluke unit near the closed end of said slot, a stabilizing unit in the form of an open box-like structure disposed at the after end of the fluke unit comprising a number of stabilizing plates projecting from both sides of the base portion of said fluke unit at spaced intervals across the overall width of said base portion, each stabilizing plate lying in a plane substantially parallel to the plane of movement of the shank about its pivot, a transverse rigid strip connecting the outer edges of said plates on each side of said fluke unit and constituting a tripping bar which together with the stabilizing plates and the fluke unit defines substantially unobstructed longitudinal through-way passages, and means associated with said tripping bar for limiting the angular movement of said shank.

2. An anchor as claimed in claim 1 in which said shank is pivotally connected to the fluke unit by means of a pin inserted through the inner end of said shank, said pin having bifurcated ends engaging the opposite edges of the slot in said fluke unit so as to overlap a portion of the opposite surfaces of said fluke unit and means for securing said pin to said fluke unit, the rear portion of said fluke unit over which the stabilizing unit extends, being of greater width than the combined overall width of the flukes, so as to provide a pair of inclined shoulder portions, one on either side of the fluke unit and both facing in the direction of travel of the anchor over and through the sea bed.

3. An anchor comprising a shank, a fluke unit formed from a single fiat plate of generally triangular shape having its base disposed at the after end of the anchor, said fluke unit having a slot formed therein extending centrally along the greater part of its length from the forward end thereof, said slot terminating in a closed end some distance from the base so as to form a pair of flukes and a connecting portion which joins the flukes together at their after ends, said shank extending'into said slot between said flukes, means for pivotally connecting said shank therein to the fluke unit near the closed end of said slot, a stabilizing unit in the form of an open box-like structure disposed at the after end of the fluke unit comprising a number of oppositely arranged pairs of stabilizing plates projecting substantially at right angles from the after ends of the opposite plane faces of the fluke unit in vertical alignment with one another and at intervals across and Within the combined overall width of the base of said fluke unit, each of said oppositely arranged pairs of stabilizing plates lying in a plane substantially parallel to the plane of movement of the shank about its pivot, a transverse rigid strip crime-sting the outer edges of the pairs of plates on each side of said fluke unit and constituting a tripping bare which together with the pairs of stabilizing plates and the fluke unit defines substantially unobstructed pairs of longitudinal through-way passages, the pair of passages defined hy the two innermost pairs of stabilizing plates being disposed centrally along the axis of the anchor and housing the means for pivotally connecting the shank to the fluke unit, means associated with said tripping bar for limiting the angular movement of the shank, and means for temporarily attaching a stock to the after end of the stabilizing unit.

4. An anchor comprising a shank, a fluke unit formed from a single fiat plate of generally triangular shape having its base disposed at the after end of the anchor, said fluke unit having a slot formed therein extending centrally along the greater part of its length from the forward end thereof, said slot terminating in a closed end some distance from the base so as to form a pair of fiukes and a connecting portion which joins the fiukes together at their after ends, said shank extending into said slot between said flukes, means for pivotally connecting said shank to the fluke unit near the closed end of said slot, a stabilizing unit in the form of an open box-like structure disposed at the after end of the fluke unit comprising a number of oppositely arranged pairs of stabilizing plates projecting substantially at right angles from the after ends of the opposite plane faces of the fluke unit in vertical alignment with one another and at intervals across and within the combined overall width of the base of said fluke unit, each of said oppositely arranged pairs of stabilizing plates lying in a plane substantially parallel to the plane of movement of the shank about its pivot with their leading edges in transverse alignment at right angles to the longitudinal axis of the anchor and inclined outwardly and rearwardly from the bases of the said stabilizing plates to provide a series of rearwardly sloping edges with respect to the direction of travel of the anchor over and through the sea bed and all positioned in a common inclined plane, a transverse rigid strip connecting the outer edges of said pairs of plates on each side of the fluke unit and constituting a tripping bar which together with the pairs of stabilizing plates and the fluke unit defines substantially unobstructed pairs of longitudinal through-way passages, the pair of passages defined by the two innermost pairs of stabilizing plates being disposed centrally along the axis of the anchor and housing the means for pivotally connecting the shank to the fluke unit, said innermost pairs of stabilizing plates being of shorter length than the two outermost pairs so as to provide a transverse passage at the rear of said plates along each plane face of the fluke unit from one outermost pair of plates to the other, and with which pair of transverse passages the longitudinal through-way passages that are formed between both inner and outer pairs of plates communicate at their open after ends, means associated with said tripping bars for limiting the angular movement of the shank, and means for temporarily attaching a stock to the after end of the stabilizing unit.

5. An anchor as claimed in claim 4 in which the individual stabilizing plates constituting the two outermost pairs are each of triangular shape with their trailing edges inclined to the axis of the triangle at the same angle as their leading edges, and their bases secured to the opposite faces of the fluke unit, and in which the individual plates of the inner pairs of stabilizing plates are constituted by the front half only of a similar shaped triangle, both inner and outer pairs of triangular shaped stabilizing plates being at the same height from both faces of the fluke unit, and having flattened apexes which form seatings to which the transverse tripping bars are secured.

6. An anchor as claimed in claim 4 in which the innermost pairs of stabilizing plates on each side of the fluke unit are provided along their inclined leading edges with recesses, and in which a shank retaining plate is secured within each recess and extends between said pairs of stabilizing plates adjacent and parallel to the tripping bars.

7. An anchor as claimed in claim 4 in which the base portion of the fluke unit on which the stabilizing unit is mounted, has its opposite edges parallel to the plane of movement of the shank about its pivot, and the outermost stabilizing plates are each in the form of a single plate extending across the fluke unit at each of said edges and secured along its center portion to the corresponding edge of the fluke unit, the leading edge of each stabilizing plate being reinforced by a rectangular plate extending outwardly from the side of said plate so as to lie in the same plane as said edge.

8. An anchor as claimed in claim 4, in which each outermost stabilizing plate situated at either side of the fluke unit has an opening formed in its rear portion for receiving a stock extending transversely of the fluke unit at the after end of the stabilizing unit, and means for locating .and temporarily securing said stock in its assembled position.

9. An anchor as claimed in claim 4 in which said flukes are each provided with a pair of longitudinal strengthening ribs formed one on either side thereof at right angles thereto and in alignment with one another, the two pairs of ribs being transversely spaced apart a distance equal to 10 that between the two innermost pairs of stabilizing plates and forming extensions of the base portions of said plates.

10. An anchor comprising a fluke plate, a pair of stabilizing plates secured one at each side of the after end of the fluke plate, each stabilizing plate comprising a single plate extending across the corresponding edge of the fluke plate so as to provide a triangular-shaped part extending outwardly from each face of the fluke plate, a shank pivotally mounted on said fluke plate, a fluke extending from the fluke plate in the plane thereof, on each side of the shank, and tripping bars extending across each' face of the fluke plate over the whole width thereof and connected at their ends to the apices of the triangularshaped parts.

11. An anchor comprising a fluke plate, a pair of stabilizing plates secured one at each side of the after end of the fluke plate, each stabilizing plate comprising a single plate extending across the corresponding edge of the fluke plate so as to provide a triangular-shaped part extending outwardly from each face of the fluke plate, a shank pivotally mounted on said fluke plate, a fluke extending from said fluke plate in the plane thereof on each side of the shank, tripping bars extending across each face of the fluke plate over the whole width thereof, and connected at their ends to the apices of the triangular-shaped parts, and means associated with said tripping bars for limiting the pivotal movement of the shank.

References Cited in the file of this patent UNITED STATES PATENTS 308,646 Williams Dec. 2, 1884 957,621 Neal May 10, 1910 1,497,693 Meyers June 17, 1924 2,249,546 Danforth July 15, 1941 2,633,626 Danforth Apr. 7, 1953 2,677,343 Shipley May 4, 1954 2,722,191 Johnson Nov. 1, 1955 

